The Sava Centre in Belgrade is not, it must be said, an inspiring building. The 1970s conference-cum-concert hall stands in a wasteland in the high- rise district of Novi Beograd. With its glassed-over entrance hall, it looks like a giant conservatory crossed with a hospital block.

Not, at first glance, an obvious place to witness a miracle. None the less, the mood at the charmless Sava Centre this week has been just as extraordinary, in some ways, as the dramatic events on the streets.

Djordje Balasevic is a fortysomething singer with receding hair and an amiable air of scruff. A very European mixture of chansonnier and raconteur - try mixing Georges Brassens and Billy Connolly and see what you get. In Serbia, he has long been enormously popular. His songs are lyrical, peppered with irony - sex, drink, pain. He has been singing for 20 years, and his following includes both the middle-aged and the young. In the past, he has been part of the staple diet of Belgrade television.

But, as this week's concert made clear, no longer. More changes will have to take place in Serbia before Balasevic again becomes the television bosses' favourite. Balasevic delivered non-stop contempt for the government of Slobodan Milosevic - its crassness, warmongering, hypocrisy, riot police, and its dead-end lack of policy. The 4,000-strong audience adored it. Old and young, they blew whistles, cheered, cried, and sat bewitched. And, above all, they laughed.

And that was the real miracle: the happiness in the hall. This was an evening of Serbian innocence. In recent years, Serbia has drowned in its own myths, always blaming others for its misfortunes. But that is no longer the only Serbia.

Balasevic chattered on, with tales of Milosevic, of politics, and of Balasevic's travels - most recently, to Britain. He described applying for the visa, the questions at Heathrow, and how he got into small-talk when he finally arrived. A new acquaintance asked where he was from. "Xcdvarqzia," came Balasevic's mumbled reply. Asked again, he repeated: "Xcdqzlavia" ... I somehow found that I had a big chocolate in my mouth," he told the packed hall on Wednesday night. Then, he was asked a third time: "Sorry, where did you say?" "Yugoslavia!" he finally declared, with a confident roar. There was laughter and recognition in the hall - recognition of the possibility that Serbs may finally get past their shame, and regain the identity which Slobodan Milosevic has made it so difficult for a self- respecting Serb to declare.

In one of the few explicitly political songs, Balasevic sang of the "bad guys, pessimists, lunatics and psychopaths who destroyed everything". But he emphasised, too, that this has not been a war which the Serbs can simply push to one side. "The generals and moustachioed majors - they are not guilty," he sang. "They just said: `Fire', and pulled the triggers. We are guilty, because we were silent." The hall erupted in applause.

For many at the concert, it was the changes in people's heads which gave most reason for optimism - not the concessions that the authorities appeared to make this week in recognising opposition election victories. Jelena Brkljacic, a 26-year-old biologist, was more optimistic than she had ever been about the prospects for a different Serbia. "Just a few months ago, I was desperate. I said to my husband: `Nothing will ever get me on the streets again'. It was too depressing. Nothing ever changed." The atmosphere of Wednesday's concert was "completely different", she said, from concerts in previous years. Her husband, Bojan, added: "Suddenly, we've got hope. Much has happened. But much more will happen, that's what counts. That makes us feel good."